JPH07204782A - Aluminum-made metallic mold - Google Patents

Abstract

PURPOSE:To obtain a metallic mold being suitable to cast a small quantity of product, such as a trial casting, by forming a surface modified layer composed of electroless nickel-plating layer on the inner surface of the metallic mold composed of Al base material. CONSTITUTION:In the metallic mold 2 consisting of the Al base material, the surface modified layer 5 is formed on the inner surface at the hollow space 3 side in contact with poured molten metal. This surface modified layer 5 is made by forming the electroless nickel-plating layer or further, dispersing ceramic fine particles in this non-electroless nickel-plating layer or forming nitride layer of titanium nitride or chromium nitride, etc., with ion-plating or forming the nitride layer with ion implantation. This surface modified layer 5 restrains the affinity between the metallic mold 2 and the molten metal, and gives the wear resistance, slipping resistance, corrosion resistance, heat resistance, etc., to the metallic mold 2, the durability and the service life of the metallic mold 2 are improved and the surface condition of the casting is made to be good.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is a mold used for casting zinc-based materials and aluminum-based materials in the machinery industry represented by the automobile industry, and is particularly useful in the development and trial production stages of new products. The present invention relates to a prototype die used.

[0002]

2. Description of the Related Art In the machinery industry represented by the automobile industry, new products are developed through several stages of trial production from the first to the fifth, and at each stage approximately 30 to 50 prototypes are produced. Is manufactured with a die made of iron-based material, and various tests are performed based on the prototype. By the way, it is not preferable to manufacture an iron mold in each of the stages and to perform a test or the like after manufacturing a prototype using the mold, because this will increase the cost.

Therefore, the following measures can be considered. (1) A method of making each prototype by hand without using a die, or changing the material of the prototype to a material that is easy to process, such as resin. It should be noted that this method may be actually used in the field at the initial trial production stage. (2) A method of manufacturing the die material using an aluminum-based material, which has a low processing cost, instead of an iron-based material. Note that this method is currently used as a mold for plastic products.

[0004]

However, each of the above two methods has the following problems. (1) In the method of manufacturing a prototype by cutting or the like without using a mold, the test result is different from that of a casting manufactured using the mold, and accurate test results cannot be obtained. (2) In the method of using an aluminum mold without using an iron mold, the molding is limited to a plastic product, and a zinc product or an aluminum product cannot be cast with the aluminum mold. This is because the melting point of the mold and the molten metal poured into it is close, and because of the strong affinity between the mold and the molten metal, the molten metal is welded to the inner surface of the mold, damaging the mold, and solidified products. It was difficult to remove from the mold, and even if it was impossible, it was limited to a very small amount. The present invention has been made to solve these problems.

[0005]

The present invention is an aluminum mold 2 characterized in that a surface modification layer 5 is formed on the inner surface of a mold 2 made of an aluminum material. The surface modification layer 5 is, for example, an electroless nickel plating layer, or a nitride layer formed by ion plating or ion implantation.

[0006]

The molten metal such as a zinc-based material poured into the mold 2 from the runner 4 is slightly cooled while passing through the sprue 4a, the runner 4 and the like, and the temperature of the molten metal by the time it enters the mold 2. Since it is slightly lower than the melting point of the mold 2, the mold itself is not damaged. In addition, the surface modification layer 5 formed on the inner surface of the mold 2, that is, the portion in contact with the poured molten metal,
The affinity between the mold 2 made of an aluminum-based material and the molten metal or solidified molded product (cast) made of a zinc-based material or an aluminum-based material is suppressed, and the cast product is easily taken out from the mold 2. Further, the surface modification layer 5 has wear resistance of the mold 2,
Slip resistance, corrosion resistance, heat resistance, etc. are improved, and the durability and life of the mold 2 are improved.

[0007]

The aluminum mold 2 of the present invention will be described in more detail below. FIG. 1 is a vertical sectional view of a casting apparatus using an embodiment of an aluminum mold of the present invention. Further, FIG. 2 is an enlarged vertical cross-sectional view showing a mold in the casting apparatus, but a fixing bolt and a runner, which will be described later, are omitted. This casting apparatus 1 performs what is called a die casting method casting. The mold 2 of the present invention is
It is divided into two, an upper mold 2a and a lower mold 2b, by a score line 1x.
In the casting apparatus 1 as well, by moving the bar 13 up and down, the pin 12 connected to the bar 12 can separate or combine the casting apparatus 1 into the upper and lower two 1a and 1b along the score line 1x. , 1b are combined and separated by the molds 2a, 2
It can be performed simultaneously with b.

The mold 2 is installed at a predetermined position of the casting apparatus 1 by a stop bolt 10 and functions as a nest. That is, when it is necessary to replace the mold 2 due to a change in the product shape or the life of the mold, it is convenient to replace only the part of the mold 2 in the casting apparatus 1, which is convenient and reduces the manufacturing cost. Useful for reduction. A desired product shape is formed in the part on the parting line 1x side where the upper mold 2a and the lower mold 2b overlap, and the hollow space 3 having the product shape is formed by overlapping the upper mold 2a and the lower mold 2b.
In order to flow the pressurized molten metal into the hollow space 3 of the mold 2, a runner 4 communicating with the hollow space 3 is formed in the upper mold 2a along the dividing line 1x. The shape and forming position of the runner 4 are changed by the mold 2, the casting apparatus 1, and the like.

The mold 2 is made of an aluminum material, and a surface modification layer 5 is formed by nitriding treatment on the inner surface of the hollow space 3 which is in contact with the molten metal to be poured. The surface modification layer 5 suppresses the affinity between the mold 2 and the molten metal, and imparts wear resistance, slip resistance, corrosion resistance, heat resistance, etc. to the mold to improve the durability and life of the mold 2. To improve
Improves the surface condition of castings. Specifically, for example, an electroless nickel plating layer is formed, ceramic particles are dispersed in the electroless nickel plating layer, or a nitride layer such as titanium nitride or chromium nitride is formed by ion plating, The surface modification layer 5 is formed on the inner surface of the mold 2 by forming a nitride layer such as titanium nitride or chromium nitride by ion implantation. The material of the mold 2 is preferably an aluminum alloy for the mold. For example, in addition to the 7000 series aluminum alloys specified in JIS, Alquin 300 (Furukawa Electric Co., Ltd.)
Of course, it is not limited to this.

Explaining the method of manufacturing the mold 2, first, an aluminum material is processed into a predetermined shape by cutting or electric discharge machining, then the surface thereof is polished, and thereafter,
It is desirable to form the surface modification layer 5 such as the electroless nickel plating layer or the nitride layer on the polished surface.

Next, a casting method using the mold 2 will be described. The aluminum mold 2 is used in casting a zinc-based material. For example, Z
It is used for casting zinc alloy die castings specified in JIS such as DC1 and ZDC2, but is not limited to this. First, as shown in FIG. 1, the mold 2 of the present invention is attached to the casting apparatus 1 with the stop bolt 10. Next, while applying the molten zinc-based material for casting to the casting apparatus 1, the sprue 4
a and the runner 4 are poured into the hollow space 3 inside the mold, and are held and cooled for a predetermined time according to the molten material, product size, product shape, etc. When the product is solidified, the upper mold 2a and the lower mold 2b And are separated together with the casting apparatus 1 and the solidified molded product (cast product) is taken out from the mold 2. At this time, the casting is taken out by the article extruding pin 11 which works to push the casting by separating the casting apparatus 1 and the mold 2.

Further, as shown in FIG. 1, the casting apparatus 1 and the mold 2 are separated from each other at the dividing line 1x, and the moving distance thereof is X shown in the figure. The separation interval X is larger than the lateral width Y of the product, and the casting product removed from the mold 2 by the product extruding pin 11 can be taken out from the gap Y. The casting thus produced is subjected to cutting processing or surface treatment, if necessary, to be a final product, which is used for various tests at the stage of developing a new product.

The aluminum mold 2 of the present invention is
It can be used not only for casting zinc-based materials but also for casting other materials. For example, it can be used for casting aluminum-based materials such as ADC1 or ADC10 or ADC12, etc., such as aluminum alloy die-casting specified in JIS, but it is better to use zinc-based materials for casting to improve the durability of the mold 2. The life and life can be extended. Further, the aluminum mold 2 of the present invention can be used not only as a prototype mold for manufacturing a prototype at the stage of developing a new product but also as a main mold for casting an actual product. Suitable for casting. Furthermore, it goes without saying that the aluminum mold 2 of the present invention can be used in a casting method other than the die casting method.

[0014]

According to the present invention, since the surface modification layer 5 is formed on the inner surface of the mold 2, the affinity between the mold 2 and the molten metal poured into the mold 2 is suppressed. It has become possible to manufacture a die for casting the above material from an aluminum-based material. As described above, according to the present invention, since the mold can be made of the aluminum-based material, the mold is lighter in weight and has improved workability and thermal conductivity as compared with the case where the mold is made of the conventional iron-based material. Can be made. When the mold is made of an aluminum-based material as in the present invention, the cutting time is 1/3 or less, the electric discharge machining time is 1/3 or less, and the thermal conductivity is higher than that of the conventional iron-based material. Is more than doubled. Therefore, it is possible to reduce the manufacturing cost of the mold 2, and it is possible to carry out tests and the like using prototypes manufactured by casting even in each of several stages of trial manufacture. As a result, the test can be performed in an environment similar to that of the actual product, which enables extremely reliable product development.

The surface modification layer 5 imparts wear resistance, slip resistance, corrosion resistance, heat resistance, etc. to the mold 2 to improve the durability and life of the mold 2, and to improve the surface of the casting. It also has the effect of improving the condition. Furthermore, by changing the surface modification layer 5, it is possible to obtain the mold 2 according to the material of the molten metal and the like, and it is possible to balance the cost and the quality of the casting with the life of the mold. For example, when the surface modification layer 5 is an electroless nickel plating layer, if ceramic fine particles are further mixed in the electroless nickel plating layer, the surface modification layer is formed as compared with the case where only the electroless nickel plating layer is formed. Furthermore, the durability and life of the mold 2 can be improved. Moreover, the mold 2 of the present invention is applicable not only to a mold for producing a prototype, but also to a main mold for casting an actual product, and in this case, it is suitable for casting a small amount of product. Can be said.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a casting apparatus using an embodiment of an aluminum mold of the present invention.

FIG. 2 is a schematic vertical cross-sectional view of one embodiment of the aluminum mold of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casting device 1x secant 2 Aluminum mold 2a Upper mold 2b Lower mold 3 Hollow space 4 Runner 4a Gate 5 Surface modification layer 10 Fixing bolt 11 Extruding pin 12 Pin 13 bar

Claims (4)

[Claims] 1. An aluminum mold, wherein a surface modification layer is formed on the inner surface of a mold made of an aluminum material. 2. The aluminum mold according to claim 1, wherein the surface modification layer comprises an electroless nickel plating layer. 3. The aluminum mold according to claim 1, wherein the surface modification layer comprises a nitride layer formed by ion plating. 4. The aluminum mold according to claim 1, wherein the surface modification layer comprises a nitride layer formed by ion implantation.